Attracting wild birds by feeding birdseed is a very popular hobby. Usually, persons who wish to attract wild birds, specifically song birds, with feed do not wish to also attract non-bird species, specifically squirrels. Squirrels enjoy eating birdseed and can discourage wild birds from visiting the birdfeeder device, especially when the squirrels are likely to consume most of the birdseed. This can be expensive as well, since feeding squirrels and such non-bird species as well as wild birds can be quite burdensome. There are many mechanisms and strategies to deny squirrels and the like access to the bird seed in a bird feeder. Most such mechanisms, as here, rely on the substantial difference between the weight of a typical squirrel and that of a desirable song bird.